Pontiac Problems? Ask a Mechanic for Answers ASAP
Hello, my name is Bobby. Thank you for the question. Is this a Grand Am or Grand Prix?
Thank you. Does the knock change as the engine warms up? Does it get louder or go away if you rev the engine?
Thank you. Start by pulling off both engine drive belts and start the engine to see if it goes away. It is common for the supercharger to fail internally and cause this. If the noise is still there with the belts removed then it may be a rod knock or a collapsed lifter. You can tell which one it is by whether the noise seems to be from the top of the engine or the bottom.
If you happen to need anything else or have more questions please let me know.